Flushing means for fluid metering apparatus and the like



United States Patent [72] Inventor Robert H. Berg 196 Clinton Ave., Elmhurst, Illinois 60126 [21] Appl. No. 748,766 [22] Filed July 30, 1968 [45] Patented Aug. ll, 1970 [54] FLUSHING MEANS FOR FLUID METERING APPARATUS AND THE LIKE 10 Claims, l Drawing Fig.

[52] U.S. Cl 137/240, 73/401, 324/71 [51] Int. Cl Fl7d 1/00, l F l 5b 21/04 [50] Field of Search 137/240, 231, 238, 237, 324/1571;73/401;141/1,11 [56] References Cited UNITED STATES PATENTS 5/1950 Young 2,713,344 7/1955 Gallistel l37/239X 2,869,078 l/l959 Coulter 324/71 3,044,483 7/1962 Wilburn l37/240X 3,154,087 10/1964 Beaver 137/15 3,190,321 6/1965 Robinson l37/l5X 3,412,749 ll/1968 McAdams 137/240 Primary Examiner- Clarence R. Gordon Attorney-Hill, Sherman, Meroni, Gross and Simpson ABSTRACT: A flushing tube has its discharge end located in the reservoir bulb near the top of one leg ofa manometer-like gauging device having a first fluid metering medium with a surface in the reservoir contacted in operation by a second fluid to be metered in an attached handling arrangement. The flushing fluid flow is not only over the surface of said metering medium but also through the handling arrangement.

Paten-ted Aug; 11, 1970 l 3,523,546

Y@ ATTORNEYS FLUSHING MEANS FOR FLUID METERING APPARATUS AND THE LIKE THE DISCLOSURE This invention relates to means for cleaning metering apparatus or exchanging or empting a metered fluid and the like, without the necessity for dismantling the apparatus and/or associated fluid handling structure.

ln that class of apparatus exemplified by automatic pipettes, i. e., Simple Automatic Pipet, William Nye, Analytical Chemistry Vol. 22, page 848 (1950) and the fluid metering apparatus in U. S. Patent 2,869,078 one leg of a U-shaped metering device carrying mercury has near its top a bulb defining a reservoir within which the surface of the mercury is exposed to a fluid to be metered or measured in an associated arrangement by the action of the mercury moving displaceably with respect to the reservoir. Where particles are entrained in the metered fluid they may tend to settle out in the reservoir and require at least periodic flushing out. When the same apparatus yis to be used for clifferentfluids, rnirttui"esl suspensions, and the like, it may beand often is desirable to flush out or empty the system including the metering reservoir andthe associated arrangement between handlings of the different fluids. Heretofore, it has been customary to effect such cleaning primarily by dismantling the apparatus and cleaning it out as by rinsing, scrubbing, and the like.

An important'o'bjecthof the present invention is to provide means for effecting cleaning of at least the reservoir surface of the fluid metering medium and desirably also of the associated metered fluid handling means without requiring any dismantling of the apparatus. v

Another object of the invention is to provide new and improved flushing means for fluid metering apparatus and the like.

A further object of the invention is to provide novel means for flushing the reservoir and the surface of fluid metering medium in such reservoir by the direct flushing flow of clean ing fluid introduced into the reservoir and subsequently flow- .'ltfhfsvsh the assssiatesmstresaid,handbag.@was.

Still another object of th ention is to provide n'ew, effiycient`,fast acting'reans foi'flshing metering'apparatus, and the like.

Other objects, featres and advantages of the present inven- Iiplwilt bs A rL1iLv-a2ParsnLfrQmthe. fsllqnislsatailsq description of a preferred embodiment thereof taken in con, junction with the accompany drawing,in which:

The single illustrative figure, partially in vertical section, shows apparatus embodying features of the invention.

As shown in the drawing the metering apparatus includes means 5 for handling fluid to be metered and metering means 7 operativelyconnected by a preferably rigid duct 8 which slopes at least slightly upwardly from the metering means to the fluid handling means. ln this instance, the apparatus is depicted as adapted to be part of a particle sensing system in which a liquid 9 having particles in suspension and contained in a container l is drawn through an orifice l1 into a tube l2 otherwise closed except at its top where it is fitted into a lower bell mouth 13 of a downward tubular extension 14 from the upper end of the conduit 8 and the lower end of an upwardly -opening tubular vacuum head l detachably connected as by means of a coupling sleeve 17 to a vacuum valve unit 18 arranged to be connected to a vacuum pump by suitable means such as conduit 19.

Extending downwardly in clearance relation within the tubular extension 14 and the orifice tube l2 and with its lower end in adjacent spaced relation to the bottom of the orifice tube lisa small diametervsucti n tube 20. Removable and lon:

gitudinallyhadjus-table mount g of the upper'ehd portion'of the tube 20 within the suction head l5 is effected in substantially fluid tight relation by means of a longitudinally spaced pair of resilient sealing rings 21 grippingly encircling the sucv parts of the handling means 5 are made from a dielectric material such as glass.

For connection with electrical particle sensing means, an electrode 24 is mounted within the tubular extension 14, and an electrode 25 is mounted in the liquid 9 within the container l0.

In the metering means 7, and responsive to vacuum condition in the handling means 5, is fluid metering medium 27 such as mercury which is non-miscible and non-absorbable with respect to the liquid 9 and is a good conductor of electricity.

v For this purpose the metering means comprises a generally U- shaped tubular structure of a dielectric material such as glass comprising?. vertical, Column les 2.8J'0insd byallrbend 29 t0 a vertical leg 30 desirably entending to a greater height than the column leg 28.Throughout tlilflerigth of thU-striuc'tu're is 'a passage 3l which is of generally small diameter ,except for a bulbous enlargement 32 adjacent to the top of the leg 28 and defining a reservoir for the mercury 27 to present a relatively large surface area, a small volume bulbous reservoir enlargement 33 intermediately in the leg 30 and a surge expansion Asafety small bulbous enlargement 33a adjacent to the upper j end of the leg 30. Intermediate its ends, the leg 28 may have a grounding electrode 34 in contact with the mercury column. Sensing apparatus control probe electrodes 35 and 37 extend into the tubular passage of the leg 30 at respectively opposite ends of the reservoir enlargement 33.

l 'For removably attachingthe metering means column 28 to the conduit 8, an upward nipple projection 38 from the top of 'the reservoir bulb 32 is connected separably as by means of a coupling 39 to a complementary downward coupling nipple extension 40 on the adjacent lower end of the conduit 8. Thereby, vacuum in the liquid handling section 5 of the apparatus causes the mercury 27 to rise in the column 28 as desired and move with respect to the electrodes 35 and 37 and lipari. closing oftlthe vacuum, Spurs@ by. @sans of rhsjyalve .18

effecting a metered drawing of the liquid `il througlfthe orifice p reservoir within the bulb 32 and over the surface of the mercury 27 conveniently and efficiently comprise a flushing fluid nozzle tube 4l extending as a stem of smaller diameter *downwardly/through the nipple 40 and forming a downward extension of or mounted in an upward lflushing-head branch extension 42 from the metering means end of the conduit 8 and preferably comprising an integral part thereof aligned with the nipple 40. Connection of the nozzle tube 41 with a source of flushing fluid may be effected in any suitable manner such as by means of a conduit 43 attached to the free end of the flushing head 42 by means of a coupling tube 44 replaceably connected to the head 42 as by means of a coupling sleeve 45. Control of the flushing fluid is by means such as a valve 47 which may be carried by the coupling tube 44. By having the discharge end of the flushing tube 41 directed to discharge into the reservoir 32 above the face of the mercury pool, the flushing fluid will sweep the mercury face and create a substantial turbulence thereabove within the reservoir under the controlled volume and velocity, to remove and flush out accumulated debris and previous metered fluid efficiently.

ln addition to flushings the mercury reservoir, the flushing fluid introduced through the tube 41 is employed to flush out the orifice tube l2. For this purpose, the relative cross-sectional areas of the flushing flow passages around the tube 41 through the nipples 38 and 40 through the conduit 8, about the tube 20 through the extension 14 and the orifice tube 12, as well as the passage through the tube 20, are predetermined to be ample to afford efficient flushing fluid flow velocity for the intended purpose and to dislodge and remove accumulated debris in the system.

To provide differential pressure for flushing fluid flow, both of the control valves 18 and 47 are opened and either pressure of the flushing fluid, or vacuum, or a combination of pressure and vacuum utilized, Flushing fluid volume and velocity are effectively controllable.

lt will be understood that modifications and variations may be effected without departing from the scope of the novel concepts of the present invention.

lclaim:

l. Flushing means for fluid metering apparatus and the like having means for handling fluid to be metered and metering means including fluid metering medium having a reservoir within which a surface of said medium is contacted by the fluid, comprising:

means for effecting a flushing flow of cleaning fluid in said reservoir and over said metering medium surface; and means for controlling said flushing flow.

2. Flushing means according to Claim l, in which said means for effecting flushing flow comprises a tube having a discharge end directed into said reservoir above said metering medium surface.

3. Flushing means according to Claim 1, including a conduit connecting said fluid handling means and said metering means, a flushing head branch on said conduit comprising part of said means for effecting flushing flow and having a flushing nozzle discharging into said reservoir.

4. Flushing means according to Claim 3, in which said metering means includes a metering medium column having a bulbous enlargement in an upper portion thereof providing said reservoir and with a connecting nipple affording communication above the reservoir, said conduit having a connecting nipple aligned with the reservoir nipple, and a coupling connecting the nipples separably, said flushing nozzle extending through said nipples into the reservoir.

5. Flushing means as defined in Claim 3, said means for controlling the flushing fluid comprising a valve connected with said flushing head branch.

6. Apparatus according to Claim 1 having in said means for handling fluid to be metered, an upright tubular member having a lower end and an upper end, an orifice tube connected to said lower end, an upper tubular head extension on said tubular member, a combination vacuum suction and flushing discharge tube extending from said head downwardly through said tubular member and through said orifice tube and having a lower end near a closed bottom of the orifice tube, and means for removably connecting said suction tube within said head.

7. Apparatus according to Claim 6, said means for connecting said suction tube in said head comprising a pair of axially spaced sealing rings engaging about the suction tube and engaging within said flushing head, and retaining means on said flushing tube operating to maintain the respective positions of the sealing rings.

8. Apparatus according to Claim 6, in which said suction tube has an air bleed hole opening into said tubular member adjacent to said head extension.

9. Apparatus according to Claim l, including a rigid conduit having said fluid handling means on one end thereof and having on its opposite end a flushing head carrying said means for effecting flushing flow of cleaning fluid, said conduit providing a passage for cleaning fluid from said reservoir to said handling means.

l0 Apparatus according to Claim 9, said handling means including an orifice tube and means to connect the orifice tube with said conduit, and a discharge passage member extending into the orifice tube, cleaning fluid from the conduit being conducted in flushing relation into the orifice tube and discharging through said passage member. 

